The present invention concerns formulated medicine for treatment and/or prevention of opportunistic infectious diseases complicated by infection with Lentivirus.
AIDS or Acquired Immunodeficiency Syndrome, one of the biggest problems in modern medicine, is an infectious disease caused by a RNA virus called Lentivirus. Viral RNA of Lentivirus, which is a Retrovirus, is transcribed into DNA by the activity of reverse-transcriptase after infection of the host cell, where it acts like a gene of the host cell. Consequently, genetic modification occurs after integration of the viral gene into the host (similar to oncogenesis), and becomes incurable. How to treat and cure the disease remains as one of the biggest problems in modern medicine. This fact causes public fear about AIDS.
HIV-1 and HIV-2, or human Lentivirus, is characterized by destroying lymphocytes having the CD4 receptor and damaging the immune system. Some viruses other than HIV-1 and HIV-2 are classified as Lentivirus: SIV causing immunodeficiency syndrome in monkeys, FIV causing feline immunodeficiency syndrome, goat arthritis virus and encephalitis virus, horse infectious viral anemia, and bovine Immunodeficiency Virus. The diseases caused by these viruses have a common characteristic in these animal species in that the animals become immunodeficient, resulting in frequent complications due to opportunistic infectious diseases. Especially in human AIDS, it is important to treat and prevent opportunistic infectious diseases to improve patients'quality of life and for prolongation of the life span of asymptomatic HIV carriers, and patients with AIDS related syndrome and genuine AIDS. The treatment and prevention of opportunistic infections are as important as the suppression of the viral proliferation using anti-viral drugs.
Opportunistic infectious disease is caused by microbes and viruses having weak pathology which scarcely invade a healthy animal with an intact immune system. Onset of AIDS is triggered by immunodeficiency caused by decrease of CD4 lymphocytes; these compromised conditions are followed by infections by various opportunistic pathogens (which are normally removed by the immune system in healthy animals). Highly characteristic opportunistic infections occur in AIDS patients as follows: pneumonia caused by respiratory infection by protozoan Pneumocystis carinii; systemic infection by Cytomegalovirus or Herpes simplex virus; and mycotic infection by Candida or Aspergillus.
In spite of the remarkable progress of antibiotics and synthetic chemotherapies (hereinafter "chemotherapy" for both), opportunistic infectious diseases are regarded as very intractable in compromised hosts (such as those having AIDS). It is known that elimination of pathogens by the host-defense system plays a decisive role during recovery from infectious disease, along with inhibition of proliferation or eradication of pathogens by chemotherapies. Since in most cases opportunistic infectious disease onsets only in a host whose host-defense system faces collapse of integration, and many pathogens begin to propagate simultaneously, it is improbable that a single chemotherapeutic drug can improve the condition. Accordingly, it is clear that opportunistic infectious disease will never be cured completely unless there is a means to restore the host-defense system simultaneously with inhibiting proliferation of pathogens with combined chemotherapies. Some current methods to improve host-defense ability of compromised hosts are known but there is none that improves host-defense ability without any side effect.